Barrie Birch, the deputy headteacher at Queens Park community school, tells a joke about parent, teacher and friends associations (PTFAs). "You know what we used to say about our old PTFA? One parent. One teacher. And it does sweet FA."

Not any longer. By any standards, parental activity at Queens Park community school (QPCS), a comprehensive in Brent, north-west London, that my two daughters go to, has been extraordinary over the past few years. Fundraising is still at the heart of its work, with a number of big money-making events on the annual calendar, including Burns night, a quiz night, an international evening and the summer fair. More than £10,000 was raised last year.

But parental enthusiasm also now supports many aspects of the curriculum at the school. There's a film club, a writers' programme and "jazz nite", a monthly event when professional musicians come in and jam with student singers and instrumentalists. Parents help out on Shout, the school magazine. A choir set up by Janis Kelly, a parent and opera singer, has performed at local venues including the Tricycle theatre. Plans are well advanced for an artist in residence, and a four-day arts festival next spring.

Where's all this energy coming from? And why? Polly Pollock, a basketmaker and freelance art teacher with two girls at the school, says: "I just feel lucky that I live near such a great comprehensive. Being involved in the PTFA and the school feels natural."

Susan Kennedy has two sons at QPCS and is running the marathon this spring as part of a school effort to raise money for two new minibuses. "On a very basic level, we help raise extra funds, which makes a big difference to what can and cannot happen in the school," she says.

At primary school level, it is common for parents to be involved. Relationships with teachers are fostered by the daily pick up and drop off at the school gate, and most young children love their mum or dad to come in to help with a cake stall or swimming lesson. Come secondary transfer, however, and close contact with both the school and other parents ceases almost overnight. Kids now make their own way to school. There is no natural way for parents to get involved and little chance to build meaningful relationships with staff bar the termly progress meetings. Some adolescents are embarrassed by the appearance of their parents, though the "squirm factor" might, paradoxically, diminish if more parents became involved.

National trend?

So are we parents at QPCS unusual, an impressively hyperactive bunch of north-west Londoners? Or is the surge of activity that we have seen a sign of a national trend towards greater parental involvement in the secondary sector?

These days, parents are exhorted by the government to take an active interest in every last detail of their children's education, a fact reflected in schemes such as Educating Parents to Raise Achievement (Epra), based on the belief that improving parental support at home can significantly raise individual student achievement. The scheme makes a distinction between parental engagement (with one's own child) and parental involvement (in the school), thought to have no significant impact on an individual child's results but to be of benefit to students as a whole.

Peter Coombes, co-chair of the school's PTFA, spots "an element of middle-class angst" in the mix. "Some parents want - or need - to scrutinise the school close up. You do notice that some people's involvement drops off once they've assured themselves that everything is OK. But that's OK, too."

Laura Warren, of the National Confederation of Parent Teacher Associations (NCPTA), says research shows a real shift in recent years. "Not only are individual children more likely to succeed with the support and involvement of their parents, but the school itself is more likely to flourish if a group of parents is involved."

Two years ago, the NCPTA set up the Learning, Education and Parental Partnership awards, which provide start-up funding for initiatives that draw more parents in.

David Harrap is one of the award-winners. His son, Nathan, attends the Villa Real school, in County Durham, for children aged 5-19 with learning difficulties and disabilities. Harrap, a market researcher, has been involved with the school since Nathan was five, but his input has increased recently. "I suppose I go in about 10 hours a week," he says.

Villa Real parents have been impressive fundraisers, contributing towards a school minibus, a sensory garden, outdoor archery facilities and a climbing wall. But there are also more imaginative projects afoot, such as Caring for the Carers, in which students and parents reverse roles. Parents come into the school, and their child might give them a massage or just do something as simple as light an aromatherapy candle for them.

Harrap acknowledges that many parents are too busy to get involved, but he is adamant about the importance of outside support. "Everyone takes care of their home. Why not look after your school?"

Sally Richardson is the extended school coordinator at Hornsea school and language college, a small rural secondary in the East Riding of Yorkshire. "Last term, there was a maths trail, involving a treasure hunt, for year 7 families," she says. "The languages department ran a family quiz night, and the English department had a 'lads and dads' day, looking at how to boost literacy through writing sports commentary among teenagers who were predicted borderline C and D grades at GCSE. The event was very, very successful."

It takes confidence to suggest ideas to an already hard-pressed subject faculty. Coombes wryly observes: "We also need to know when to back off. Teachers are really busy."

I was one of several parents who approached QPCS in early 2006 to see if we could help bring writers into school, to bring a fun element to an often fact- and test-heavy national curriculum. The English department was welcoming, yet firm from the outset about what it could and couldn't manage. Demands from one publisher that a visiting writer's book be purchased, read and analysed by over 40 children before the talk were politely rejected as impracticable.

Bestselling writers

But the rewards of the Write Stuff, as our programme has come to be known, have been immense. Students from year 7 to the sixth form have benefited from talks and workshops from, among others, Francesca Simon, author of the bestselling Horrid Henry books, prize-winning poets Daljit Nagra and Sophie Hannah, and novelists Maggie Gee, Kate Muir and Bernardine Evaristo. Our local bookshop now helps with promotion.

Such projects have undoubtedly boosted the school's local profile. Five years ago, many middle-class parents, impressed by the apparently superior facilities and more selective intake of private, grammar and faith schools, had an unjustly negative opinion of the school.

All that has changed. Now heavily oversubscribed, QPCS is the local school of choice. Mike Hulme, the headteacher, says: "Using parent skills in contributing to curriculum and enrichment activities has been a true liberator in cementing confidence."

Hulme acknowledges that there can be a downside to all this enthusiasm. "There are occasions when the 'parent voice' can be a little irritating," he says. "Consultation groups might have misunderstood their remit, and a plethora of clip-art flyers did cause initial concern to some staff."

But the biggest remaining challenge is to widen the parent group, to see, in Hulme's words, "parent involvement really reflecting an accurate profile of our diverse intake".

Coombes agrees. "Our active membership clearly does not reflect the ethnic and cultural diversity of the school. To do that, we'd need to bring in many more black and Asian parents, which is a challenge the PTFA and the school need to address together."